The prior art is replete with numerous examples of sorting devices of various designs, and which are utilized to transport a supply of objects to be sorted along a course of travel and into an inspection station; form an image of the objects in the inspection station; determine the characteristics of the objects of interest in the inspection station by reviewing the image of the objects; identify unacceptable or foreign objects in the inspection station; transmit a sorting signal to a rejection station positioned downstream from the inspection station; and remove the unacceptable or foreign objects from the product stream which has passed through the inspection station.
Various arrangements and schemes have been developed, over time, to inspect all the surface areas of an object passing through an inspection station. Such prior art devices have included arrangements for imaging the objects passing through the inspection station from both above and below or on opposite sides of the object as the objects pass through the inspection station, or, releasing the respective objects traveling in the product stream so that they individually pass, unsupported, across a gap or move under the influence of gravity into free fall while an image of the object is taken from one or both sides of the object.
While these prior art designs have worked with varying degrees of success, many shortcomings have detracted from their usefulness. One of the chief shortcomings associated with the practices which have been utilized, heretofore, relates to the interpretation of the resulting images which are formed, and where the shadows of the object passing through the inspection station often impairs a proper identification of defective or unacceptable objects or foreign material passing through the inspection station. Attempts to remedy this problem have remained outside the grasp of designers and fabricators of such inspection and sorting devices.
An object imaging assembly which avoids the detriments associated with the prior art practices which have been utilized, heretofore, is the subject matter of the present invention.